An Overview of the Use of Argumentation Schemes in Case Modeling
6. Arguments from Generally Accepted Practices
What is interesting here is the notion that legal rules partly define a concept that may be partly derived from, and may be held to be desirably consistent with previously existing customs practices and understanding of those en-gaged in common activities like hunting, fishing and gold mining. To illustrate this point, Gray (2002, 6) formulated six important concepts or rules about the understanding of first possession of baseballs accepted by fans and other par-ticipants in the sport of baseball. Two of these rules can be used to illustrate how each rule acts as a partial of definition of the notion of a catch. One is the
An Overview of the Use of Argumentation Schemes in Case Modeling 87
negative rule that a catch does not occur simply because the ball hits the fan on the hands or enters the pocket or webbing of the fan’s baseball glove. Another is the positive rule stating that a catch does occur when the fan has the ball in his hand or glove, the ball remains there after its momentum has ceased, and even remains there after the fan makes incidental contact with a railing, wall, the ground or other fans who are attempting to catch the baseball or get out of the way.
These commonly accepted rules show how legal rulings based on applying open-textured legal concepts to new cases can partially depends on evidence drawn from commonly accepted practices that exist prior to the legal frame-work. The use of such arguments prior to the legal framework can be repre-sented by the scheme for argument from popular practice (Walton, Reed and Macagno, 2008, 314).
Major Premise: A is a popular practice among those who are familiar with what is acceptable or not in regard to A.
Minor Premise: If A is a popular practice among those familiar with what is acceptable or not with regard to A, that gives a reason to think that A is acceptable.
Conclusion: Therefore, A is acceptable in this case.
Critical Questions
CQ1: What actions or other indications show that a large majority accepts A?
CQ2: Even if large majority accepts A as true, what grounds might here be there for thinking they are justified in accepting A?
It is clear from the statement of the minor premise that such arguments are defesaible. They can be argued against, and it can be argued that they are not applicable.
7. Conclusions
This paper has examined a special group of schemes that are typically tightly woven in together when arguing from one case to another as in CBR. Once they are clearly distinguished, we can get a better perspective on how the CBR process in law retrieves a past case that is similar to the target case, in order to solve the target problem. The problem is very often how to classify something.
In an easy case, the classification problem can be solved by simply fitting it in under a previously accepted rule, whether it is a legal rule or a generally ac-cepted practice, or a definition that has already been acac-cepted as authoritative.
Douglas Walton 88
In a hard case, this may not solve the problem because, for one thing, concepts are open-textured, and for another thing, because of this, it is generally not possible to formulate a set of necessary and sufficient conditions that are com-plete to solve the problem.
How the six argument factor evaluation structures for argument from precedent (Wyner and Bench-Capon, 143-146, 2007) fit into the framework I have outlined here is not still entirely clear to me, possibly because I’ve never encountered anything like this device before in previous argumentation theory.
It’s something new. However, it strikes me that the device is extremely useful, because it provides a way of evaluating an argument from precedent while it is being put forward during the argumentation stage, and where it is being at-tacked by arguments from opposing precedents.
How does the process of applying these schemes to cases work, in general?
The main points in the procedure can be set out as follows.
• The process uses general rules derived from legally authoritative sources by statutory interpretation.
• It uses arguments from analogy to previous decided cases.
• The new version of argument from precedent is based on argument from analogy.
• When so based, it can be evaluated by the six factor evaluation struc-tures.
• It may also be based on argument from an established rule.
• In some instances, legal reasoning uses argument from generally accept-ed practices in specific kinds of practical activity domains.
• Significantly, it uses and arrives at classifications based on these rules.
• Instead of fixed definitions, it uses defeasible partial definitions in the form of necessary and sufficient condition rules.
• It applies these rules to the problematic case that needs to be decided by examining and weighing the arguments pro and contra based on the evidence from these and other sources.
The best we typically have are some general rules that are defeasible and that may be more or less on point. However, we have tried to show in this paper that such a set of rules can provide what can be called a defeasible definition, a definition that is not complete for making a classification beyond further arguments, but can move the argumentation in a case forward by supporting other arguments.
References
1. keVin Ashley, ‘Case-Based Reasoning’, Information Technology and Law-yers, ed. Arno R. Lodder and Anja Oskamp, Berlin, Springer, 2006, 23-60.
An Overview of the Use of Argumentation Schemes in Case Modeling 89
2. kAtie Atkinson, treVor Bench-cAponAnd peter McBurney, ‘Arguing About Cases as Practical Reasoning’, Proceedings of the 10th International Con-ference on Artificial Intelligence and Law, ed. Giovanni Sartor, New York, ACM Press, 2005, 35-44.
3. floris Bex, henry prAkken, chris reed, chris And douglAs WAlton, ‘To-wards a Formal Account of Reasoning about Evidence: Argumentation Schemes and Generalizations’, Artificial Intelligence and Law 11, 2003, 125-165.
4. thoMAs f. gordon, ‘Constructing Arguments with a Computational Model of an Argumentation Scheme for Legal Rules’, Proceedings of the Eleventh International Conference on Artificial Intelligence and Law, 2007, 117-121.
5. thoMAs f. gordonAnd douglAs WAlton, ‘Pierson v. Post Revisited’, Com-putational Models of Argument: Proceedings of COMMA 2006, ed. P. E.
Dunne and T. J. M. Bench-Capon, Amsterdam, IOS Press, 2006, 208-219.
6. thoMAs f. gordon, henry prAkkenAnd douglAs WAlton, ‘The Carneades Model of Argument and Burden of Proof’, Artificial Intelligence, 171, 2007, 875-896.
7. BriAn e. grAy, ‘Reported and Recommendations on the Law of Capture and First Possession: Popov v. Hayashi’, Superior of the State of California for the City and County of San Francisco, Case no. 400545, November 6, 2002. Available May 24, 2009 at: http://web.mac.com/graybe/Site/Writ-ings_files/Hayashi%20Brief.pdf
8. H. L. A. hArt, ‘The Ascription of Responsibility and Rights’, Proceedings of the Aristotelian Society, 49, 1949, 171-194. Reprinted in Logic and Lan-guage, ed. A. Flew, Oxford, Blackwell, 1951, 145-166.
9. H. L. A. hArt, The Concept of Law, Oxford, Oxford University Press, 1961.
10. ronAld p. loui, ‘Hart’s Critics on Defeasible Concepts and Ascriptivism’, Proceedings of the Fifth International Conference on Artificial Intelligence and Law, New York, ACM Press, 1995, 21-30. Available at: http://portal.
acm.org/citation.cfm?id=222099
11. douglAs WAlton, chris reed And fABrizio MAcAgno, Argumentation Schemes, Cambridge, Cambridge University Press, 2008.
12. lloyd l. WeinreB, Legal Reason: The Use of Analogy in Legal Argument, Cambridge, Cambridge University Press, 2005.
13. AdAM Wyner, treVor Bench-cAponAnd kAtie Atkinson, ‘Arguments, Val-ues and Baseballs: Representation of Popov v. Hayashi’, Legal Knowledge and Information Systems (JURIX 2007), Amsterdam, IOS Press, 151-160.
14. AdAM WynerAnd treVor Bench-cApon, ‘Argument Schemes for Legal Case-Based Reasoning’, Legal Knowledge and Information Systems (JURIX 2007), A. Lodder and L. Mommers, eds, Amsterdam, IOS Press, 2007, 139-149.